Asphalt or flexible pavement is typically built with several layers to form a layered system with better materials at the top where the stress intensity is high and inferior materials at the bottom where the stress intensity is low. The top layer, called the surface course, is typically made of an asphalt mixture. All types of failure or distress can be classified by whether they are structural or functional failures and load associated or non-load associated distresses.
Most bituminous adhesives or binders that are used for pavement materials are derived primarily from fossil fuels. Nevertheless, with petroleum oil reserves becoming depleted and the subsequent urge to reduce fossil fuel usage, there is a drive to develop and produce binders from alternative sources, particularly from biorenewable resources. Over the years, biorenewable natural resources including sugars, triglyceride oils and proteins have been tested as alternative sources for producing adhesives and binders. For example, adhesives derived from soy protein, starch, cellulose and other polysaccharides have been extensively used for adherents such as wood, paper, plastic, metal, leather and glass. Due to the availability of large quantities of biorenewable sources such as triglyceride oils, proteins, starch and other carbohydrates from different botanical sources, there are virtuous technical and economic prospects in utilizing them to produce bio-binders.
Recently, through the application of scientific research and development, a range of different vegetable oils have been investigated to determine their physical and chemical properties to study their applicability to be used as bio-binders in the pavement industry. Applicants have found this development to be useful in overcoming the deficiencies in the art.